21663411111620 has 12 divisors (see below), whose sum is σ = 45493163334444. Its totient is φ = 8665364444640.

The previous prime is 21663411111619. The next prime is 21663411111731. The reversal of 21663411111620 is 2611111436612.

It can be written as a sum of positive squares in 2 ways, for example, as 10055380524484 + 11608030587136 = 3171022^2 + 3407056^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 541585277771 + ... + 541585277810.

It is an arithmetic number, because the mean of its divisors is an integer number (3791096944537).

Almost surely, 2^{21663411111620} is an apocalyptic number.

21663411111620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21663411111620 is an abundant number, since it is smaller than the sum of its proper divisors (23829752222824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21663411111620 is a wasteful number, since it uses less digits than its factorization.

21663411111620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083170555590 (or 1083170555588 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The spelling of 21663411111620 in words is "twenty-one trillion, six hundred sixty-three billion, four hundred eleven million, one hundred eleven thousand, six hundred twenty".